Firefox 153 has arrived across Windows, macOS, Linux, and Android, delivering a blend of usability enhancements and critical security hardening. The latest release introduces HDR video playback for Windows users, a native QR code sharing tool, and more than 60 patched vulnerabilities. Mozilla also pushed updates to its Extended Support Release (ESR) channels and addressed a known post-installation crash affecting some early adopters.
Firefox 153 update: What’s new and what changed
For Windows users, the most notable multimedia upgrade is native High Dynamic Range video playback. To use this feature, you must enable HDR mode in your Windows display settings. The enhancement expands streaming support beyond standard dynamic range, offering deeper contrast and richer color depth. However, Mozilla notes that displays limited to “HDR video streaming” capabilities are not currently supported. Additionally, portrait-oriented smartphone videos remain unsupported in this build.
The built-in PDF viewer and editor now includes file merging capabilities. You can combine multiple PDF documents by dragging them directly into the PDF sidebar. Users can also insert images as new pages within existing PDF files, streamlining document management without relying on third-party tools.
Sharing links has become more frictionless with a new QR code generator. This tool creates a scannable code for any webpage, making it easy to transfer URLs to mobile devices without using Firefox Sync or third-party services. The browser also improves privacy visibility by highlighting the location-sharing icon in red when a website actively accesses your location data, giving you clearer feedback about when your position is being tracked.
The free VPN introduced in Firefox 149 continues to offer access to virtual locations, temporarily expanded to 28 countries with unlimited data through the end of August. This offer is currently available to users in the US, UK, Canada, France, and Germany. While the VPN remains subject to certain limitations, the temporary unlimited data window provides a practical opportunity for users to test the feature extensively.
Security updates in Firefox 153
According to Mozilla’s Security Advisory 2026-68, the Firefox 153 update resolves over 63 vulnerabilities. Of these, 60 were reported by external security researchers, including three identified by OpenAI Codex Security. Mozilla classifies 17 of these as high risk, with four posing a sandbox escape threat that could allow malicious code to break out of the browser’s isolated environment.
Another 35 vulnerabilities are rated medium risk, while the remainder fall into the low-risk category. The advisory also lists three additional high-risk entries stemming from internally discovered memory management errors. These vulnerabilities are grouped by affected applications and versions, providing transparency for enterprise administrators and security professionals tracking patch deployment.
ESR versions updated
Firefox ESR 140.13.0 and 115.38.0 have also been released. The latter is restricted to Windows 7, 8.1, and macOS 10.12 through 10.14, reflecting Mozilla’s gradual phase-out of support for older operating systems. These ESR builds address at least 32 vulnerabilities in version 140.13 and 14 in version 115.38, including two classified as critical.
Firefox 153 will form the foundation for the next ESR generation, replacing ESR 140 this October. ESR 115 will continue receiving security patches until March 2027, with Mozilla reassessing support extensions as that deadline approaches. Organizations relying on older ESR versions should plan migration timelines accordingly to avoid unsupported environments.
Post-install crash fix
Following the Firefox 153 update release, some users encountered browser crashes when internal files failed to load or upon launching after an update. Mozilla recommends downloading a fresh installer from firefox.com and reinstalling over the existing installation. Saved data, including bookmarks and passwords, will remain intact as they are stored separately from application files. If you experience this issue, a clean reinstall should resolve the corruption without data loss.
Source: PCWorld
Over to you: Will you enable HDR video playback in Firefox 153, or stick with your current browser settings?
